Also, the 1N400x series diode can be exchanged for an S1x series if an SMT diode is needed.
I think xrk971 was talking about the SMSL 3118. Until your post, I had no idea SMSL had this TPA3116 board: she looks like a beauty! I just ordered the 3118 and now regret it.
Thanks Doctor J -- yeah, there are so many options in the 3116/3118/3110 boards, it's starting to get hard to keep track of. I've actually read that Sure is bringing out a finished 3116 amp, too (I think first week of December was the most recent info).
I think xrk971 was talking about the SMSL 3118. Until your post, I had no idea SMSL had this TPA3116 board: she looks like a beauty! I just ordered the 3118 and now regret it.
I did not know that SMSL has a 3116 board. Is there a link?
Those were just values I "had on hand".
The mute on powerup is almost 2 seconds...yes, more than needed.
🙂
There is a listing on shenzhenaudio, and also on Amazon (with shenzhenaudio as the seller):
http://www.shenzhenaudio.com/smsl-sa-60-60wpc-tpa3116-class-d-digital-amplifier-hifi-air-core-inductance-desktop-amplifier.html
http://www.amazon.com/SMSL-SA-60-Digital-Amplifier-silver/dp/B00PA3QIOE/
SMSL SA-60 60WPC TPA3116 Class D Digital Amplifier HiFi Air Core Inductance Desktop Amplifier
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Nice looking speaker! What is the design based on? bass reflex or TL? It has a very narrow baffle and the sound could probably be vastly improved if you used a baffle step correction filter to attenuate the highs to balance out the highs vs bass. Something like a 1mH and 10ohm resistor in parallel and that put in series between amp and positive driver terminal.
Good luck.
Air core usually means very very bad for class D because of their excessive EMI.
Technically air cores are perfectly linear (in theory) however due to their excessive size and the number of turns required it makes them extremely good antennas.
Usually you should avoid using air cores in switching designs at any cost. Toroids and shielded ferrite core inductors specifically developed for switching designs is the preferred choice. Air cores are the preferred choice in loudspeakers where the signal is usually low frequency (audio range) and fairly sinusoidal. In switching designs the signal the inductors see is high frequency (radio range) and almost perfect square waves which makes completely different demands on component choices.
In general terms; only an amateur designer with no knowledge of switching designs would choose air core inductors. My best advice is to stay away from designs using them. You really really don't want them in your house, or even your neighbours house.
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Given the 400kHz carrier frequency would the 1/4-wave antenna length have to be of order much larger to be a good radiator? There are high speed switch transients that are faster of course and maybe those are the problem spikes? In any case, this amp is in a sealed metal box which should help. If someone with a RF meter handy can do a survey of these boards that would be great. Otherwise we are all speculating how bad it is.
It might be ampboard itself that needs shielding from aircores, bottom side Multi layers pcb usually a better place for aircores...
It's square waves. There will be harmonics to almost infinity (limited only by slew rate). Use this the above amp with the lid off and I'll wager that you'll lose 1-2 bars on your cell phone reception. Even with the lid on bluetooth device ranges in the same room are probably halved.
Not only that but it will also transmit out through the input and output wires. Being in a metal box only helps so much.
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lots of sales on Ali:
New SMSL SA 60 60WPC TPA3116 Class D Digital Amplifier HiFi Desktop Amplifier(Upgraded version of SA 50)-in Amplifier from Electronics on Aliexpress.com | Alibaba Group
Looks like this would be the amp of the year!
New SMSL SA 60 60WPC TPA3116 Class D Digital Amplifier HiFi Desktop Amplifier(Upgraded version of SA 50)-in Amplifier from Electronics on Aliexpress.com | Alibaba Group
Looks like this would be the amp of the year!
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***
I just purchased the SMSL SA-60 amp. I'm an extra class amateur radio operator, have been for the past 46 years, and am active on the HF bands (1.8 MHz through 30 MHz). All kinds of electronics have been thrown out of my home (figuratively, if not literally) because they caused a miniscule increase in RF noise level (which can make the difference between making a DX (distant) contact and not). Light bulbs, computers, toys, coffee makers, remote controls - out the window.
With the SA-60 turned on vs. turned off, I can hear no change in noise level on the HF bands, with the HF transceiver plugged into the same AC line at the amp, sitting 10 feet away from the amp, and using a dipole antenna that runs twenty feet above the amp's location.
I hear no noise at all introduced into the audio system in which the amp is being used - and I'm acutely sensitive to audio noise. For example, I recently found that my HTPC was introducing a very low level audio noise because one screw was not fully tightened on the outside of the case.
The fully enclosed metal case of the SA-60 is doing a good job of blocking any radiated noise and noise is not getting out through the AC line or the line input or speaker lines.
At the same time, the SA-60 sounds wonderful. It's just a couple of hours old and seems to be improving with time. I have no other 3116 amps at this point to compare it to, but have LOTS of amps, both solid state and tube (high, mid and low end) to compare it to, and it's an excellent amp (within its power output limits, which are after all about 25 watts at reasonable THD levels). I'll be experimenting with better power supplies (inlcuding high current 12 volt battery) to see what difference that makes.
If this amp had noise problems you would be advised to duck while driving past my home, because it would be flying at high speed after having been thrown out the window.
Les
That's great to hear that it's not causing you any problems on your particular amp, Les H.
I stand by my general critique of air core inductors though. They offer no advantages in audio quality over better alternatives. I suppose you could just throw out the amp and use the case though. That seems decent enough quality.
I stand by my general critique of air core inductors though. They offer no advantages in audio quality over better alternatives. I suppose you could just throw out the amp and use the case though. That seems decent enough quality.
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Hold on - solid core inductors can saturate and limit output. This is not an issue with air core. If noise problems are not an issue - and they are not with this design based on my sensitive equipment tests - I'd prefer air core.
Also, the SA-60 carries both FCC and CE certifications, which include RF noise emission testing and limits.
Regarding RF noise from amps (or any electronics for that matter): wouldn't the amount of power going into the emitter make a difference? Be it an air-core inductor or an actual explicit broadcast antenna, it seems like how much RF you generate must be proportional to power. What's the power "threshold" for when the RF actually becomes a problem?
The tpa3116 is a very efficient chip, so there's not a lot of "waste power" left over to use for RF pollution, right?
For example, in my setup (nearfield, moderate listening levels), I estimate I'm only putting about one watt (usually less) into each speaker. So that's two watts total output from the amp, and let's say it's only 50% efficient (overly conservative estimate), so that means two watts are going to "waste". If all of that is converted to RF noise, what does that mean in practical terms? What's the worst-case scenario for RF pollution that one can do with two watts of power?
Let's say someone's pushing a constant 20 watts each into two speakers, so 40 watts total output from the amp. At this level the tpa3116 should be operating closer to 90% efficiency, but let's say 80% for the sake of argument. That implies 40/.8 = 50 watts input power, and 50-40 = 10 watts of waste. How much "broadcast power" do you get with 10 watts?
These are honest questions, by the way, not rhetorical or subtle arguments.
The tpa3116 is a very efficient chip, so there's not a lot of "waste power" left over to use for RF pollution, right?
For example, in my setup (nearfield, moderate listening levels), I estimate I'm only putting about one watt (usually less) into each speaker. So that's two watts total output from the amp, and let's say it's only 50% efficient (overly conservative estimate), so that means two watts are going to "waste". If all of that is converted to RF noise, what does that mean in practical terms? What's the worst-case scenario for RF pollution that one can do with two watts of power?
Let's say someone's pushing a constant 20 watts each into two speakers, so 40 watts total output from the amp. At this level the tpa3116 should be operating closer to 90% efficiency, but let's say 80% for the sake of argument. That implies 40/.8 = 50 watts input power, and 50-40 = 10 watts of waste. How much "broadcast power" do you get with 10 watts?
These are honest questions, by the way, not rhetorical or subtle arguments.
This amp can output a maximum of 4A per channel. That's 2A per inductor. Most inductors used for the TPA3116 handles at least twice that if not 3 times.
Saturation is not an issue.
Air core inductors however typically have higher ESR. Often twice or 3 times as much. That would limit output and affect audio quality.